Valve for apportioning preheated and non-preheated air to an internal combustion engine

Claim 1

Valve for apportioning preheated and non-preheated air to an internal combustion engine, comprising a valve body having an inlet for preheated air, an inlet for non-preheated air, a common outlet from the valve leading to an intake conduit for the engine, and a thermostatically controlled flap valve mounted for pivotal movement about an axis that passes through the valve body, between extreme end positions in one of which a first flap portion on one side of said axis closes said inlet for preheated air and in the other extreme end position of which said first flap portion closes said inlet for non-preheated air, said valve flap having a second flap portion on the side of said axis opposite said first flap portion, said valve body having a balancing chamber which communicates on both sides of said axis with the portion of the interior of the valve body in which said first flap portion moves, said second flap portion being disposed in said balancing chamber and dividing said balancing chamber into two portions separated from each other by said second flap portion, said flap portions being of such dimensions and being so arranged that the forces exerted on the flap valve as a result of the air flow through the valve body give rise to oppositely directed torques of substantially the same magnitude.